KANSAS CITY, Mo. (AP)  A suspicious package that smelled like ammonia sickened several people at an IRS building in downtown Kansas City, Missouri, on Friday, federal authorities said.

Local officials said about 10 people reported being ill, including vomiting and nausea, after the package arrived at the sprawling building’s mailroom Friday morning.

U.S. Department of Homeland Security spokeswoman Lucy Martinez said some people reported feeling ill with “watery eyes,” and several people were evaluated and treated at hospitals. Two people were treated at nearby St. Luke’s Hospital, where they were in good condition, spokeswoman Laurel Gifford said.

Martinez said the package was an envelope that smelled like ammonia, though no other details were released about the envelope’s contents or where it may have originated.

She said the investigation has been taken over by the U.S. Treasury Inspector General for Tax Administration, a division in the IRS that investigates fraud.

The Federal Protective Services, which responds to terrorism and criminal acts against U.S. government infrastructure, also is involved in the investigation. The agency responded to the incident along with local officials.

Kansas City Fire Department spokesman James Garrett said a hazardous materials team checked the package for gasses and fumes but didn’t find anything before it was turned over to federal authorities.

The IRS building wasn’t evacuated during the incident. Business returned to normal about two hours after the incident began.